The present invention relates to lawn mowers having a grass-clipping collection bag, and in particular to lawn mowers having an indicating assembly for indicating when the collection bag is substantially full.
It is known in the prior art to provide lawn mowers which provide a collection bag for collecting bag clippings. Some of such lawn mowers provide and indicating assembly for indicating to the operator that the collection bag is substantially full and needs to be dumped.
Many mowers provide arrangement wherein a bag full detection will automatically cut-off the mower engine. This design is rather inflexible. For example, this design may cause the engine to shut down when there is only a small amount of grass remaining to be cut, and where the operator would prefer to finish cutting the additional amount prior to dumping the collection bag.
Other indicating assemblies provided with mowers have been unnecessarily complex, expensive, or unreliable. For example, U.S. Pat. No. 5,388,394 discloses a system which detects a build-up in air pressure in a discharge duct. This system does not detect grass clipping levels directly and relies on other factors which may or may not be directly related to a bag-full condition. Other systems, rely on the weight of the collection bag (see U.S. Pat. No. 4,981,011) or a sensor in the mower chute (see U.S. Pat. No. 5,325,650) for detecting a bag-full condition. Another system, disclosed in U.S. Pat. No. 5,321,939 utilizes a relatively expensive light sensor system that provides a bag-full indication when a light-blocking state of the sensor continues for a period of time longer than a predetermined period of time. None of these systems directly detect the level of grass clippings within the bag, and thus do not provide an accurate bag-full indication.
It is an object of the present invention to overcome the problems associated with the prior art noted above. This object is achieved by providing a lawn mower comprising a frame, an engine mounted on the frame, a cutting mechanism driven by the engine constructed and arranged to cut grass and to generate grass clippings, a bag for collecting said grass clippings, and a bag-full indicating assembly. The bag-full indicating assembly includes an indicator that indicates to a mower operator that the bag is substantially full in response to a bag-full signal, and a switch which can be activated to generate the bag-full signal. The switch comprises a grass-contacting member extending into the bag. The grass-contacting member is movable from a non-activated state to an activated state by being displaced by grass clipping build-up within the bag. The switch thereby enables the bag-full signal for the indicator so that the indicator indicates to the mower operator that the bag is substantially full.
In a preferred embodiment, the grass-contacting member comprises an elongate flexible member being in a normally substantially straight configuration and being flexibly bent in response to a build-up of grass clippings within the bag. The elongate flexible member comprises internal conductive contact members disposed in normally spaced non-conductive relation to one another. The conductive contact members are moved into conductive engagement with one another to activate the switch upon flexing of the elongate flexible member to predetermined extent upon build-up of grass clippings in the bag.
It is also an object of the present invention to provide a ride-on mower that achieves the benefits noted above.